I use about 300mls of cream and maybe a bit of milk to about 3-4 potatoes. I mix the cream up with 1 teaspoon of veggie stock powder, 1 teaspoon of dried onion flakes, 1 teaspoon of mustard and 2 crushed garlic cloves. Then I slice and layer the potatoes in a dish, pouring some cream mixture on every couple of layers until the whole thing is assembled. Top with a little grated cheese then cover and bake at 200 degrees for about 30-40mins, remove cover when potatoes are getting soft and allow cheese to brown.